Method for evaluating the mechanical performances of a switchgear device and switchgear device for implementation of said method

Abstract

The invention relates to a method for evaluating the mechanical performances of a switchgear device comprising at least one pole. Each pole comprises: a pair of contacts ( 12, 14 ); a support arm ( 16 ) for a first contact ( 14 ); a mechanism ( 22 ) for driving the support arm ( 16 ) comprising a rotary poles shaft ( 20 ) and energy accumulation means capable of driving a movement of the said arm in order to place the contacts ( 12, 14 ) in an open position. The method consists in: measuring the angle of rotation (θ) of the poles shaft ( 20 ) over a period of opening the contacts ( 12, 14 ); retrieving from the measurements at least one specific value; comparing the said specific value with specific initial operational specifications of the switchgear device; diagnosing the mechanical wear performances of the drive mechanism ( 22 ) as a function of a comparative state between the specific values obtained and those of the operational specifications.

The invention claimed is: 
     
       1. A method for evaluating mechanical performances of a switchgear device comprising at least one pole, each pole comprising:
 a pair of contacts that are mobile with respect to each other between an open position and a closed position; 
 a support arm for a first contact; 
 a drive mechanism configured to drive the support arm, comprising:
 a rotary poles shaft and at least one rod which couples the drive mechanism to the support arm in a pivoting manner, 
 an energy accumulator configured to drive a movement of the said arm in order to place the contacts in an open position; 
 
 wherein the method comprises:
 measuring an angle of rotation of the poles shaft over a period of opening the contacts; 
 retrieving from the measurements at least one specific value depending on a first point of inflection on a curve of variation of the angle of rotation of the poles shaft, the said point of inflection corresponding to the time at which the poles shaft reaches a maximum speed of rotation and where the electrical contacts lose contact; 
 comparing the said specific value with initial operational specifications of the switchgear device; 
 diagnosing the mechanical wear performances of the drive mechanism as a function of a comparative state between the specific values obtained and those of the operational specifications. 
 
 
     
     
       2. The method according to  claim 1 , further comprising:
 determining a first specific value equal to a first angle necessary for reaching the first point of inflection; 
 comparing the said specific value with a theoretical reference value extracted from specific initial operational specifications of the switchgear device; 
 diagnosing the wear of electrical contacts according to a comparative state between the determined specific value and the theoretical reference value taken from the operational specifications. 
 
     
     
       3. The method according to  claim 1 , further comprising:
 determining a second specific value equal to a first time necessary for reaching the first point of inflection; 
 determining a third specific value equal to a second time necessary for reaching a second point on the curve of variation of the angle of rotation, the said second point corresponding to a theoretical final angle of rotation reached when the main pair of mobile contacts is in an open position; 
 calculating the time elapsed between the first and second times; 
 comparing the time elapsed between the first and second times with a reference value representing the operation of a switchgear device that is not worn; 
 diagnosing the wear of the electrical contacts as a function of a comparative state between the determined specific values and the reference values taken from the operational specifications. 
 
     
     
       4. A switchgear device configured to perform the method according to  claim 1 , the switchgear device comprising:
 the pair of contacts that are mobile with respect to each other between the open position and the closed position; 
 the support arm for the first contact; 
 the drive mechanism configured to drive the support arm, comprising:
 the rotary poles shaft and the at least one rod which couple the drive mechanism to the support arm in the pivoting manner, and 
 the energy accumulator configured to drive the movement of the said arm in order to place the contacts in the open position; and 
 
 a plurality of identical poles and a poles shaft common to all of the poles, the poles shaft being the axis of rotation of the drive mechanisms. 
 
     
     
       5. The switchgear device according to  claim 4 , wherein the support arm of a first contact comprises a first part carrying the first contact and a second part, the two parts sliding with respect to each other so that, in the closed position of the pair of contacts, the second part can take up a first docking position and a second end of travel position in which the first part is inserted in the second part. 
     
     
       6. The switchgear device according to  claim 4 , wherein the drive mechanism of the poles shaft comprises a toggle device coupled with a tripping hook and an opening spring in order to move the support arm of the mobile contact, the device comprising two rods. 
     
     
       7. The switchgear device according to  claim 4 , wherein the drive mechanism of the poles shaft comprises a reset device having an energy accumulator system with an elastic device comprising at least one closing spring in order to move the mobile contact towards the closed position, the setting of the closing spring being operated by a resetting cam driven in rotation by at least one of means of a manual lever or a servomotor. 
     
     
       8. The switchgear device according to  claim 4 , further comprising a rotation sensor configured to determine an angle of rotation of the poles shaft, wherein the rotation sensor includes a component that is disposed on the poles shaft. 
     
     
       9. The switchgear device according to  claim 8 , wherein the rotation sensor comprises a magnet disposed on the axis of rotation and a first detector positioned on the casing of the switchgear device, wherein the magnet and the first detector are configured to communicate without contact. 
     
     
       10. The switchgear device according to  claim 8 , wherein the rotation sensor comprises a toothed wheel disposed on the axis of rotation and a second detector placed on the casing of the switchgear device, wherein the toothed wheel and the second detector are configured to communicate without contact.